TW202018762A - Coating film formation method and coating film formation device - Google Patents

Abstract

An object of the invention is to quickly form a coating film having a film thickness of high uniformity within the substrate plane. A coating film formation method of the invention includes: a step of holding a substrate using a substrate holding section, a step of forming an airflow on the surface of the substrate by exhausting the substrate surroundings, a coating liquid supply step of supplying a coating liquid for forming a coating film to the surface of the substrate, an airflow control step of moving a cover member that covers the substrate from a first position to a second position with respect to the substrate to which the coating liquid was supplied, thereby forming an airflow in the gap formed between the cover member and the surface of the substrate that has a higher flow rate than the airflow formed when the cover member is at the first position, followed by a film thickness distribution adjustment step of rotating the substrate at a second rotation speed which is faster than a first rotation speed so as to adjust the film thickness distribution of the coating film by spinning off the coating liquid from the peripheral section of the substrate.

Description

Coated film forming method and coated film forming device

This specification relates to a coating film forming method and a coating film forming device.

In the manufacturing process of semiconductor elements, we apply various coating solutions such as a corrosion inhibitor to a semiconductor wafer (hereinafter referred to as a wafer) that is a circular substrate to perform a film forming process. Patent Document 1 describes that when drying a resist applied to a wafer, an annular member along the wafer circumferential direction is arranged on the wafer to rectify the airflow on the wafer. [Previous Technical Literature] [Patent Literature]

Patent Literature 1: Japanese Patent Laid-Open No. 2017-92392

[Problems to be solved by the invention]

This specification provides a technique that can quickly form a coating film with a high uniformity and a uniform thickness in the surface of a substrate. [Method of solving the problem]

The coating film forming method of this specification includes: a holding procedure to hold the substrate by the substrate holding portion; an airflow forming procedure to exhaust the periphery of the substrate to form an airflow on the surface of the substrate; a coating liquid supply procedure to The coating liquid used to form the coating film is supplied to the surface of the substrate; the air flow control program moves the coating member covering the substrate relative to the substrate to which the coating liquid has been supplied from the first position to the second position, and At the gap formed between the coating member located at the second position and the surface of the substrate, forming the air flow to have a flow velocity greater than that when the coating member is located at the first position; and a film thickness distribution adjustment procedure, Then, the substrate is rotated at a second rotation speed higher than the first rotation speed to shake off the coating liquid at the peripheral portion of the substrate to adjust the film thickness distribution of the coating film. [Effect of Invention]

According to the present specification, a technique is provided for rapidly forming a coating film with a high uniformity and a uniform thickness in the surface of a substrate.

[Preferable embodiment of the invention]

The resist film forming apparatus 1 which is one embodiment of the coating film forming apparatus of the present specification will be described with reference to the longitudinal sectional side view of FIG. 1 and the top view of FIG. 2. The resist film forming apparatus 1 includes a rotating chuck 11 that is a substrate holding portion, for example, a vacuum substrate that is a circular substrate with a diameter of 300 mm, that is, a rear central portion of a wafer W, thereby holding the wafer W horizontally. The rotating chuck 11 is connected to the rotating mechanism 12 and rotates around the vertical axis by the rotating mechanism 12. In addition, a cup portion 14 is provided so as to surround the wafer W held by the rotary chuck 11 to prevent each chemical liquid from the wafer W from scattering. The bottom of the cup-shaped portion 14 is provided with a liquid discharge port 15. In addition, an exhaust pipe 16 is provided at the bottom of the cup 14 to exhaust the inside of the cup 14 during the processing of the wafer W. By evacuating the inside of the cup 14, the surface of the wafer W is evacuated from around the wafer W.

Symbol 17 in the figure is three vertical lifting pins arranged around the rotating chuck 11 and vertically lifted by the lifting mechanism 18 to transfer the wafer W between the rotating chuck 11 and a substrate transport mechanism (not shown) . A fan filter unit (FFU) 19 is provided above the cup-shaped portion 14 and supplies clean air to the wafer W placed on the rotary chuck 11. The air supplied to the wafer W is exhausted by the exhaust pipe 16 described above. In addition, the support portion 37 provided around the rotary chuck 11 supports the back cleaning nozzle 38. The back surface cleaning nozzle 38 sprays the solvent of the resist to the peripheral edge portion of the back surface of the wafer W to perform cleaning.

The etching resist film forming apparatus 1 includes an etching resist supply nozzle 21, for example, which ejects the etching resist vertically downward. This resist supply nozzle 21 is connected to a resist supply mechanism 22 that stores the resist. The corrosion inhibitor supply mechanism 22 includes a pump, a valve, or the like, and supplies the corrosion inhibitor to the corrosion inhibitor supply nozzle 21. The viscosity of the corrosion inhibitor stored in the corrosion inhibitor supply mechanism 25 is, for example, 50 cP to 1000 cP. The resist supply nozzle 21 is supported by the front end portion of the arm 23, and the base end side of the arm 23 is connected to the moving mechanism 24. The structure is such that the resist supply nozzle 21 is freely moved in the horizontal direction by the arm 23 by the moving mechanism 24 and freely moved up and down. The symbol 25 in FIG. 2 is a guide that moves the arm 23 horizontally, and the symbol 26 in FIG. 2 is a waiting area outside the cup portion 14 where the resist supply nozzle 21 waits.

In addition, the etching resist film forming apparatus 1 includes a solvent supply nozzle 31 that ejects the solvent vertically downward, for example. This solvent supply nozzle 31 is connected to a solvent supply mechanism 32 that stores the solvent, and the solvent supply mechanism 32 supplies the solvent to the solvent supply nozzle 31. The solvent supply nozzle 31 is used to remove the unnecessary resist film on the peripheral portion of the wafer W. The solvent supply nozzle 31 is supported by the front end portion of the arm 33, and the base end side of the arm 33 is connected to the moving mechanism 34. The configuration is such that the solvent supply nozzle 31 is freely moved in the horizontal direction and freely raised and lowered by the arm 33 by the moving mechanism 34. The symbol 35 in FIG. 2 is a guide that moves the arm 33 horizontally, and the symbol 36 in FIG. 2 is a waiting area outside the cup 14 where the solvent supply nozzle 31 waits.

Furthermore, the resist film forming apparatus 1 is provided with a ring plate 41 that is a circular ring-shaped member so as to be positioned above the wafer W placed on the rotary chuck 11. A circular opening 42 is formed in the center of the ring plate 41. Moreover, the lower surface of the ring plate 41 faces the wafer W placed on the rotary chuck 11 and covers the wafer W. In a plan view, the center of the ring plate 41, that is, the center of the opening 42 is aligned with the center of the wafer W placed on the spin chuck 11. Therefore, the ring plate 41 is formed along the circumferential direction of the wafer W.

The diameter A1 of the opening 42 shown in FIG. 2 is, for example, 30 mm to 80 mm. The length A2 from the center of the opening 42 to the peripheral end of the ring plate 41 is, for example, 120 mm to 145 mm. Therefore, the center portion and the peripheral portion of the wafer W are not covered by the ring plate 41. For the sake of explanation, the area covered by the ring plate 41 forming the covering member in the wafer W may be described as the middle portion. The ring plate 41 is connected to the elevating mechanism 44 via the support member 43, and elevates at the ascending position (first position) indicated by a chain line in FIG. 1 and the ascending position shown by the solid line in FIG. 1 (the first position) Between two locations).

The resist film forming apparatus 1 is provided with a control unit 10 which is a computer. The control unit 10 is installed with programs stored in a storage medium such as an optical disk, a hard disk, an MO (Magneto Optical Disk), a memory card, and a DVD. The installed program has commands (each step) programmed to transmit control signals to each part of the resist film forming apparatus 1 to control its operation. Specifically, the change of the rotation speed of the wafer W by the rotation mechanism 12 is controlled by a program, the movement of the resist supply nozzle 21 and the solvent supply nozzle 31, and the movement from the resist supply mechanism 22 to the resist supply nozzle 21 The supply and interruption of the corrosion inhibitor and the lifting and lowering of the ring plate 41 are performed.

Next, the wafer W processed by the resist film forming apparatus 1 will be described with reference to FIG. 3. A concave-convex pattern is formed on the surface of the wafer W. On the surface of the wafer W shown in FIG. 3, the area surrounded by the chain line is enlarged and displayed in front of the chain line arrow, and an example of the concave-convex pattern is shown in this enlarged view. In this example, a plurality of grooves (recesses) 51 are formed in the longitudinal direction and the lateral direction so that the surface of the wafer W is divided into a matrix. The convex portion surrounding the groove 51 is indicated by a symbol 52, and the convex portion 52 is, for example, square in plan view. A vertical cross-sectional side view of the wafer W is shown in front of the blank arrows in FIG. 3. The depth B1 of the groove 51 (the height of the convex portion 52) is, for example, 1 μm to 15 μm, and more specifically, for example, 8 μm. The width B2 of the groove 51 is, for example, 10 μm to 5000 μm, and more specifically, for example, 200 μm. The width B3 of one side of the convex portion 52 is, for example, 10 μm to 5000 μm, and more specifically, for example, 2800 μm. In addition, the concavo-convex pattern is not limited to the shape shown in FIG. 3, and the technique of this specification can also be applied in the case where a substrate on which the concavo-convex pattern is not formed is processed.

Next, the outline of the processing performed by this resist film forming apparatus 1 will be described. In this resist film forming apparatus 1, a resist is applied to the wafer W forming the concave-convex pattern as described above by spin coating, and the resist is dried by the rotation of the wafer W to form the resist film membrane. However, when the wafer W is rotated at a high rotation speed to dry the resist, the wafer W in the radial direction has a film thickness in the concave portion that constitutes the concave-convex pattern, compared to the peripheral portion of the wafer W As for the film thickness on the side, the film thickness on the center portion side is large. That is to say, in the surface of the wafer W, there may be a case where the uniformity of the thickness of the resist film in the concave portion becomes low.

This is because when the rotational speed of the wafer W is high, there is a large difference between the centrifugal force acting on the central portion side of the wafer W and the centrifugal force acting on the peripheral edge side, the viscosity of the corrosion inhibitor is high, And the above concave-convex pattern is formed. If stated in detail, because the viscosity of the corrosion inhibitor is relatively high, the fluidity of the corrosion inhibitor is largely affected by the centrifugal force. In other words, in the wafer W, the resist is more likely to move outside on the peripheral edge side, but the resist is less likely to move outside the wafer W on the center portion side of the wafer W. In other words, the resist is likely to remain on the center portion side of the wafer W, and the resist is not likely to remain on the peripheral edge side of the wafer W. In addition, since the above-mentioned uneven pattern is formed, the resist needs to overturn the unevenness in order to move to the outside of the wafer W, so the resist is likely to remain on the center side of the wafer W with a small centrifugal force. As a result, As mentioned above, the film thickness in the radial direction is not uniform. Then, in the resist film forming apparatus 1, after the resist is applied to the entire surface of the wafer W, the wafer W is rotated at a low rotation speed, and the resist on the surface of the wafer W is dried.

As described above, when the wafer W is rotated at a low rotation speed, the flow rate of the airflow on the surface of the wafer W is small, so that the drying speed of the resist becomes slow, which leads to a reduction in output. Therefore, in the resist film forming apparatus 1, when the resist is dried at the lower rotational speed as described above, the ring plate 41 is positioned at the aforementioned lowered position. 4 and 5 are schematic diagrams of the airflow when the ring plate 41 is located at the ascending position and the descending position, respectively. The reason for arranging the ring plate 41 as described above will also be described with reference to these FIGS. 4 and 5. In Figs. 4 and 5, the airflow is indicated by a blank arrow. In addition, the symbol 20 in the figure is a corrosion inhibitor.

When the ring plate 41 is in the raised position, the distance between the surface of the wafer W and the ring plate 41 is large. Therefore, the air supplied by the FFU 19 winds down below the ring plate 41, and then is directed downward, and is supplied to the wafer W with high uniformity. on. The air supplied to the wafer W as described above flows to the outside of the wafer W and is exhausted.

On the other hand, when the ring plate 41 is in the lowered position, a gap G with a small height is formed between the surface of the wafer W and the lower surface of the ring plate 41. In this state, part of the air supplied by the FFU 19 is blocked by the ring plate 41 and flows toward the center of the wafer W and flows into the opening 42 of the ring plate 41. Then, this air merges with the air supplied from the FFU 19 directly to the wafer W toward the center.

Therefore, the flow rate of the air supplied to the central portion of the wafer W is increased compared to the state where the ring plate 41 is in the raised position, whereby the velocity of the air flow on the central portion of the wafer W becomes larger. In addition, the air collected in the central portion of the wafer W is exhausted in the cup portion 14 and flows toward the outside in the middle portion of the wafer W. In the middle part, a gap G with a small height is formed between the ring plate 41 and the wafer W, that is, the flow path is narrow, so that the air passing through the middle part is located at an ascending position than the ring plate 41 The situation flows at a higher speed. As described above, the exposure to the air flow at a relatively high speed makes the drying of the resist in the center and middle of the wafer W faster.

Among them, the centrifugal force acting on the peripheral end of the wafer W is lower in the case where the wafer W is rotated at a lower rotational speed as described above to dry the resist, and, as described above, because the viscosity of the resist Higher, so the surface tension of the corrosion inhibitor is high. Therefore, as described above, when the wafer W is rotated at a low rotation speed, the resist is not easily detached from the peripheral end of the wafer W. On the other hand, there will be doubts that the use of centrifugal force from the center of the wafer W to the peripheral edge of the supply of the corrosion inhibitor, resulting in a large amount of corrosion inhibitor accumulated in the peripheral edge of the wafer W, wafer W The thickness of the peripheral portion is greater than the thickness of the central portion and the middle portion of the wafer W. In order to prevent such an increase in the film thickness of the peripheral portion, the ring plate 41 is set so as not to cover the peripheral portion of the wafer W, that is, a configuration that is open when viewed from above the wafer W.

In detail, regarding the airflow flowing from the center portion to the peripheral portion on the surface of the wafer W, the smaller the height of the space on the surface of the wafer W, that is, the narrower the flow path, the larger the velocity. Therefore, the peripheral portion of the wafer W has a slower air flow rate than the middle portion of the wafer W, and the resist is not likely to dry. When the resist on the peripheral portion of the wafer W is not dried as described above, the rotational speed of the wafer W is increased to remove the resist on the peripheral portion of the wafer W and remove it from the wafer W . This suppresses the increase in the film thickness at the peripheral portion of the wafer W, and controls the film thickness distribution to a uniform film thickness over the entire surface of the wafer W. When the rotation speed of the wafer W is increased as described above, when the ring plate 41 is in the lowered position, there is a possibility that the airflow on the wafer W is turbulent, and the uniformity of the film thickness distribution cannot be sufficiently increased, so The ring plate 41 is moved to the raised position. Therefore, when the resist is removed, the gap between the ring plate 41 and the wafer W is larger than when the wafer W is rotated at a lower rotation speed to dry the resist.

In addition, Patent Document 1 arranges the ring plate close to the wafer W to suppress turbulence on the surface of the wafer W when the wafer W is rotated at a relatively high rotation speed of 1800 rpm. However, it is not described that when the wafer W is rotated at a relatively low speed as in the resist film forming apparatus 1, a ring plate is arranged to promote drying of the resist.

The operation of the above-mentioned resist film forming apparatus 1 will be described in order with reference to the timing chart of FIG. 6 and the action diagrams of FIGS. 7 to 11. In the timing chart, the rotation speed (unit: rpm) of the wafer W is set as the vertical axis. First, the air supply from the FFU 19 and the exhaust in the cup portion 14 are performed, and the wafer W is placed on the rotary chuck 11 with the ring plate 41 in the raised position, and the back surface of the wafer W is sucked Central department. Next, the resist supply nozzle 21 is positioned above the wafer W, and the resist is supplied to the center of the wafer W. The wafer W is rotated at, for example, 1500 rpm (time t1), and the resist 20 is extended to the peripheral portion of the wafer W (FIG. 7 ).

When the resist 20 spreads over the entire surface of the wafer W, the rotation speed of the wafer W is reduced to, for example, 200 rpm (time t2), and thereafter, the ring plate 41 is located at the lowered position (time t3, FIG. 8). As described above, the flow velocity of the air flow on the surface becomes higher at the center and middle of the wafer W, and the resist 20 is quickly dried (FIG. 9 ). After that, the ring plate 41 is moved to the raised position, and the rotation speed of the wafer W is increased to, for example, 1200 rpm (time t4), and the resist 20 on the peripheral portion of the un-dried wafer W is thrown away, and the residual An etching resist film 30 is formed on the surface of the wafer W with the resist 20 (FIG. 10 ).

Thereafter, the supply of the solvent 40 from the solvent supply nozzle 31 to the peripheral portion of the wafer W and the supply of the solvent from the back surface cleaning nozzle 19 to the back surface of the wafer W are performed to remove unnecessary corrosion of the peripheral portion of the wafer W Film 30, and clean the back of the wafer W (FIG. 11). Thereafter, the supply of the solvent 40 from the solvent supply nozzle 31 and the back surface cleaning nozzle 19 is stopped, and the rotation of the wafer W is stopped (time t5), and the processing of the wafer W in the resist film forming apparatus 1 is ended (FIG. 12 ).

According to this etching resist film forming apparatus 1, the wafer W is rotated at a lower rotation speed with the ring plate 41 at the lowered position, and thereafter the rotation speed is increased. As a result, the resist can be quickly dried to form the resist film 30 to increase the throughput, and the resist film 30 can be formed in such a manner that the uniformity of the film thickness in the in-plane portions of the wafer W is high. In order to improve the uniformity of the amount of the etching resist in the surface of the wafer W, the rotation speed (first rotation speed) of the wafer W at the time t2 to t4 is, for example, 10 rpm to 500 rpm, and preferably 10 rpm to 200 rpm. In addition, as for the rotation speed (second rotation speed) after time t4, as long as the corrosion inhibitor can be removed from the peripheral portion of the wafer W, it is, for example, 1000 rpm or more. In addition, the rotation speed at the time t1 to t2 for spreading the resist on the peripheral portion of the wafer W is a rotation speed (third rotation speed) greater than the rotation speed at the time t2 to t4 for extending as described above. The time t2 to t4 is, for example, 10 seconds to 300 seconds, more specifically, for example, 60 seconds, and the time t4 to t5 is, for example, 3 seconds to 30 seconds, and more specifically, for example, 20 seconds.

In addition, after increasing the rotation speed at time t4, the rotation speed may be reduced, and the solvent may be supplied from the solvent supply nozzle 31 and the back cleaning nozzle 19 at such reduced rotation speed. Specifically, it is set as follows: the proper rotation speed for removing the resist is greater than that for removing the resist film on the peripheral portion of the wafer W and cleaning the back surface of the peripheral portion of the wafer W Appropriate speed. In this case, the corrosion inhibitor can be flung off at an appropriate speed, and thereafter, the solvent is processed at an appropriate speed. However, in order to reliably prevent the airflow on the surface of the wafer W from decreasing at the time t2, the ring plate 41 is moved to the lowered position at time t3, but the ring plate 41 may be moved to the lowered position at time t2. In addition, in the above process, the rotation speed is changed at time t4 and the start movement of the ring plate 41 is performed, but the movement of the ring plate 41 may be started after time t3 and earlier than time t4, and may be performed after the movement is started Speed change.

The ring plate 41 is configured to move laterally between the outside of the cup-shaped portion 14 and the wafer W, but it may also be set to be on the wafer W at times t3 to t4 described above, and the time outside the cup W The outside of the shape 14. In this case, the outer side of the cup portion 14 is at the first position, and the wafer W is at the second position, as in the previous embodiment. In addition, when the rotation speed of the wafer W is lifted off by the corrosion inhibitor, the ring plate 41 is moved to the outside of the cup portion 14. That is, the ring plate 41 is retracted from the wafer W. In addition, instead of raising and lowering the ring plate 41, the distance between the wafer W and the ring plate 41 may be adjusted by using the lift cup 14, the rotating chuck 11 and the rotating mechanism 12. That is, as far as the ring plate 41 is concerned, as long as the wafer W can be rotated at a relatively low speed from time t2 to t4, the position (cover position) of the covered wafer W and the position other than the cover position can be relatively moved. can. The covering position is the position where the velocity of the air flow on the surface of the wafer W is higher than when the ring plate 41 is arranged at a position other than the covering position.

In addition, in the above example, the lower surface of the ring plate 41 is a horizontal plane, but it is not limited to the horizontal plane as described above, and may be configured as an inclined surface, for example. That is, the height of the gap G in FIG. 1 may be different in each part of the lower surface of the ring plate 41, and the height of the gap G is, for example, 1 mm to 20 mm. However, the ring-shaped member like the ring plate 41 is not limited to being arranged on the wafer W as a covering member to control the air flow. For example, a plurality of holes may be formed in the region of the plate-shaped covering member whose bottom surface faces the wafer W, and the region of the covering member facing the center of the wafer W. The air supplied from the FFU 19 is supplied to the surface of the wafer W in a shower state through the plurality of holes.

In order to make the drying of the corrosion inhibitor in the peripheral portion of the wafer W slower than the inner portion of the peripheral portion, the ring plate is not limited to the above-mentioned configuration, and may be the configuration of the ring plate 61 as shown in FIG. 12. The difference between the ring plate 61 and the ring plate 41 will be mainly described. The peripheral edge side of the ring plate 61 is curved with respect to the central portion side. The peripheral portion side of the ring plate 61 is formed to face the first portion 62 of the peripheral portion of the wafer W, and the lower surface thereof is formed as an inclined surface that rises toward the peripheral end. The center portion side of the ring plate 61 is formed to face the second portion 63 of the middle portion of the wafer W, and the lower surface thereof is formed to be horizontal and to face the middle portion of the wafer W. With the configuration similar to the ring plate 61 described above, the gap G is wider toward the peripheral end of the wafer W on the peripheral portion of the wafer W. As described above, the smaller the gap G, the higher the flow velocity of the airflow toward the periphery of the wafer W. Therefore, the flow velocity of the airflow on the peripheral portion of the wafer W is smaller than the middle portion of the wafer W. Therefore, drying of the resist 20 on the peripheral portion of the wafer W can be suppressed.

In addition, FIG. 13 shows a ring plate 64 which is another configuration example of the ring plate. The ring plate 64 will be described centering on the difference from the ring plate 41. The ring plate 64 is formed with an opening 42 and includes a main body portion 45 that is a ring plate raised and lowered by a lifting mechanism 44. Here, the body portion 45 is configured so that the adapter 46, which is a ring plate, can be freely attached and detached. The outer diameter of the adapter 46 is larger than the outer diameter of the body portion 45, and the adapter 46 is installed on the peripheral edge side of the body portion 45. Therefore, the area where the peripheral portion of the wafer W is covered differs when the adapter 46 is mounted and when it is not mounted. That is, the adapter 46 is a member for adjusting the width of the area exposed on the peripheral portion of the wafer W. The chain line in the figure shows the adapter 46 mounted on the body portion 45, and the solid line in the figure indicates the adapter 46 detached from the body portion 45.

The adapter 46 can be used as a countermeasure to eliminate the difference in the dryness of the corrosion inhibitor of each device, or in the case where it is difficult to adjust the drying of the corrosion inhibitor by adjusting the rotational speed and other processing formulas when starting the device, for example. use. In addition, as for the adapter 46, it may be determined that it can be freely raised and lowered by the elevating mechanism like the main body 45. Moreover, when the adapter 46 is used, it can be moved to the position connected to the body portion 45 (the position of the chain line in the figure), and when not in use, it can be moved to a position away from the body portion 45 upward ( The position of the solid line in the figure). That is, the adapter 46 can be attached to and detached from the body portion 45 for the operator, and can also be provided with an attachment and detachment mechanism for aligning the adapter 46 to the body portion as the lifting mechanism for the adapter 46 described above 45 loading and unloading.

In the above example, the corrosion inhibitor is used as the coating liquid. However, when the coating liquid for forming another coating film such as a chemical liquid for forming an anti-reflective film or a chemical liquid for forming an insulating film is used, the present invention can also be applied. Instruction manual technology. In addition, it should be understood that the embodiments disclosed in this specification are illustrative and not restrictive in all points. The above-mentioned embodiments may be omitted, replaced, or changed in various forms without departing from the scope of the attached patent application and its gist.

(Evaluation test) Hereinafter, the evaluation test carried out in connection with this manual will be described. Evaluation Test 1 For the evaluation test 1 (1-1 to 1-4), after applying the resist to the plurality of wafers W using the above-mentioned resist film forming apparatus 1, the resist is dried in such a manner that they are different from each other . Furthermore, the film thickness of the resist film at each position on the diameter of the wafer W is measured. For the evaluation test 1-1, after the corrosion inhibitor is spread over the peripheral portion of the wafer W as in the previous embodiment, the rotation speed of the wafer W is set to 1000 rpm, and the ring plate is set at the raised position to make the resistance The etchant dries. In the evaluation test 1-2, the rotation speed of the wafer W is set to 1000 rpm as in the evaluation test 1-1, but the ring plate 41 is positioned at the lowered position to form the above-mentioned gap G to dry the corrosion inhibitor. As for the evaluation test 1-3, the rotation speed of the wafer W is set to 100 rpm, and the test is performed in the same manner as the evaluation test 1-1. As for the evaluation test 1-4, the crystal sets the rotation speed of the circle W to 100 rpm, and also performs the test in the same manner as the evaluation test 1-2. In addition, the ring plate used in each evaluation test included in this evaluation test 1 is different from the ring plate 41 described above, and the peripheral portion of the wafer W is also covered.

14 and 15 are graphs showing the results of this evaluation test 1. The vertical axis and the horizontal axis of these graphs show the measured film thickness of the resist (unit: nm) and the distance (mm) from the center of the wafer W, respectively. Regarding the distance from the center of the wafer W, the value of + is shown on one end side and the value of-is shown on the other end side, respectively. In Fig. 14, the results of the evaluation test 1-1 are displayed in solid graphs, and in the dotted line graphs, and in Fig. 15, the results of the evaluation tests 1-3 are displayed in solid lines. The graph is displayed, and the results of the evaluation tests 1-4 are displayed as a dotted line graph.

If the results of the evaluation tests 1-1 and 1-2 are observed from FIG. 14, it is known that when the wafer W is rotated at 1000 rpm, a small gap G is formed on the wafer W by the ring plate 41, as compared with When the gap G is not formed, the uniformity of the film thickness decreases. When the maximum value of the film thickness-the minimum value of the film thickness is defined as the total thickness of the film, the total thickness of the film in the case where the gap G is formed is approximately the total distance of the film thickness in the case where the gap G is not formed 2 times.

If the results of the evaluation tests 1-3 and 1-4 are observed, when the wafer W is rotated at 100 rpm, the uniformity of the film thickness of the wafer W is the case where the gap G is formed and the gap G is not In this case, there is little difference in film thickness over the entire distance, and among them, the gap G is slightly smaller. Therefore, I have confirmed that in this evaluation test 1, when the gap G is formed by using the ring plate 41 to dry the resist, it can be rotated at a lower rotational speed, thereby increasing the in-plane resistance of the wafer W The uniformity of the film thickness of the etched film.

Evaluation Test 2 For the evaluation test 2-1, ethyl lactate, which is a liquid, was applied on the surface of the wafer W, and was rotated at 100 rpm using the resist film forming apparatus 1 to volatilize it. During this rotation, the gap G is formed by the ring plate. Then, the evaporation rate of ethyl lactate in the radial portions of the wafer W was measured. As the evaluation test 2-2, a test was carried out in approximately the same manner as the evaluation test 2-1, wherein this evaluation test 2-2 was performed by a corrosion inhibitor coating device without a ring plate. Therefore, the formation of the aforementioned small gap G is not performed in this evaluation test 2-2.

Fig. 16 is a graph showing the results of evaluation test 2. The vertical axis and the horizontal axis of the graph show the evaporation rate of ethyl lactate (unit: m/sec) and the distance from the center of the wafer W (unit: mm), respectively. In this FIG. 16, the results of the evaluation test 2-1 are shown by solid lines, and the results of the evaluation test 2-2 are shown by dotted lines, respectively. I have confirmed from evaluation tests 2-1 and 2-2: in both the case where the ring plate is provided and the case where the ring plate is not provided, the volatilization speed on the peripheral portion of the wafer W is greater than the volatilization on the side of the central portion of the wafer W speed.

Evaluation Test 3 The evaluation test 3 is explained below. For the evaluation test 3-1, the corrosion inhibitor was applied by the corrosion-resistant film forming apparatus 1 and was dried by rotating at 100 rpm for a predetermined time. Furthermore, the film thickness distribution in the radial direction of the wafer W is measured. In this evaluation test 3-1, when the corrosion inhibitor was dried, the aforementioned gap G was formed by the ring plate. In addition, as evaluation test 3-2, approximately the same test as evaluation test 3-1 was performed. In this evaluation test 3-2, as for the ring plate, a shape different from that used in the evaluation test 3-1 is used.

FIG. 17 is a graph showing the results of evaluation test 3, and shows the relationship between the film thickness and the distance from the center of wafer W in the same manner as FIGS. 14 and 15 of evaluation test 1. In these Figs. 17, the results of the evaluation test 3-1 are represented by circled points, and the results of the evaluation test 3-2 are represented by square coordinate points. From the graph of FIG. 17, I know that the film thickness on the peripheral portion of the wafer W is large. From the results of evaluation test 3 and the results of evaluation test 2 above, I know that the distribution of the evaporation rate of ethyl lactate is related to the distribution of the film thickness of the corrosion inhibitor. Therefore, it is expected that, for example, the ring plate can be configured as in the foregoing examples to suppress the drying on the peripheral portion of the wafer W, thereby further surely suppressing the increase in the film thickness of the peripheral portion of the wafer W.

G: gap W: Wafer 1: Corrosion-resistance film forming device 10: Control Department 11: Rotating chuck 12: Rotating mechanism 14: Cup 15: Drain port 16: Exhaust pipe 17: Lifting pin 18: Lifting mechanism 19: Fan filter unit (FFU) 21: corrosion inhibitor supply nozzle 22: Corrosion inhibitor supply mechanism 23: Arm 24: mobile mechanism 25: Guide 26: Waiting area 31: Solvent supply nozzle 32: Solvent supply mechanism 37: Support Department 38: Rear cleaning nozzle 41: Ring plate 42: opening 43: Support component 44: Lifting mechanism

FIG. 1 is a longitudinal sectional side view of an etching resist coating apparatus according to an embodiment of this specification. FIG. 2 is a plan view of the aforementioned resist coating device. FIG. 3 is an explanatory diagram showing an example of a wafer processed by the aforementioned resist coating device. FIG. 4 is an explanatory diagram for explaining the airflow around the wafer. FIG. 5 is an explanatory diagram for explaining the airflow around the wafer. FIG. 6 is a bar graph showing an example of changes in the rotation speed of the wafer. FIG. 7 is a process diagram showing the coating process of the wafer. FIG. 8 is a process diagram showing a coating process for wafers. FIG. 9 is a process diagram showing the coating process for the wafer. FIG. 10 is a process diagram showing a coating process for wafers. FIG. 11 is a process diagram showing a coating process for wafers. 12 is a longitudinal cross-sectional side view showing a modification of the ring plate provided in the above-mentioned resist coating device. 13 is a longitudinal cross-sectional side view showing a modified example of a ring plate provided in the above-mentioned resist coating device. Figure 14 is a graph showing the results of the evaluation test. Figure 15 is a graph showing the results of the evaluation test. Figure 16 is a graph showing the results of the evaluation test. Figure 17 is a graph showing the results of the evaluation test.

G: gap

W: Wafer

1: Corrosion-resistance film forming device

10: Control Department

11: Rotating chuck

12: Rotating mechanism

14: Cup

15: Drain port

16: Exhaust pipe

17: Lifting pin

18: Lifting mechanism

19: Fan filter unit (FFU)

21: corrosion inhibitor supply nozzle

22: Corrosion inhibitor supply mechanism

31: Solvent supply nozzle

32: Solvent supply mechanism

37: Support Department

38: Rear cleaning nozzle

41: Ring plate

42: opening

43: Support component

44: Lifting mechanism

Claims (10)

A coating film forming method, including: The holding process, the substrate is held by the substrate holding part; Airflow formation procedure, exhausting the periphery of the substrate to form an airflow on the surface of the substrate; The coating liquid supply procedure supplies the coating liquid used to form the coating film to the surface of the substrate; The air flow control program moves the covering member used to cover the substrate from the first position to the second position relative to the substrate that has been supplied with the coating liquid, and the covering member located at the second position and the first position At the gap formed between the surfaces of the substrate rotating at the rotation speed, the air flow is formed to have a flow velocity greater than that when the covering member is at the first position; and A film thickness distribution adjustment procedure, and then the substrate is rotated at a second rotation speed higher than the first rotation speed, to shake off the coating liquid at the peripheral portion of the substrate and adjust the film thickness distribution of the coating film. For example, the method for forming a coating film according to item 1 of the patent application scope, in which The airflow control program includes the following process: forming the airflow so that the drying of the coating film on the peripheral portion of the substrate is slower than the drying of the coating film on the central portion of the substrate than the peripheral portion. For example, the method for forming a coating film according to item 1 of the patent application scope, in which The covering member is an annular member formed along the circumferential direction of the substrate. For example, the method for forming a coating film according to item 1 of the patent application scope, in which The coating liquid supply procedure includes the following procedure: rotating the substrate at a third rotation speed greater than the first rotation speed, so that the coating liquid supplied to the central portion of the substrate extends over the peripheral portion of the substrate. For example, the method for forming a coating film according to item 1 of the patent application scope, in which The film thickness distribution adjustment procedure is when the gap formed between the surface of the substrate and the covering member is larger than the size of the gap in the air flow control procedure, or when the covering member is withdrawn from the substrate State. The coating film forming method according to any one of the items 1 to 5 of the patent application scope, wherein, The first rotation speed is 10 rpm to 500 rpm. The coating film forming method according to any one of the items 1 to 5 of the patent application scope, wherein, The second morning at 09:58 2020/4/15 am at 09:58 2020/4/15 rotation speed is above 1000 rpm. The coating film forming method according to any one of the items 1 to 5 of the patent application scope, wherein, The substrate supplied with the coating liquid has a concave-convex pattern formed on its surface. The coating film forming method according to any one of the items 1 to 5 of the patent application scope, wherein, The covering member is an annular member formed along the circumferential direction of the substrate, The ring-shaped member is configured such that its peripheral end is located closer to the center of the substrate than the peripheral end of the substrate; or it has a ring-shaped first portion opposed to the peripheral edge portion of the substrate and opposite to the substrate The second portion of the ring-shaped area further inside the peripheral edge portion, and the height from the substrate to the first portion is greater than the height from the substrate to the second portion. A coating film forming device, comprising: The substrate holding part holds the substrate; A rotating mechanism to rotate the substrate held by the substrate holding portion; The cup-shaped portion surrounds the substrate held by the substrate-holding portion, and a gas flow is formed on the surface of the substrate by exhausting the inside of the cup-shaped portion; A nozzle to supply the coating liquid used to form the coating film to the center of the surface of the substrate; The covering member moves relative to the substrate held by the substrate holding portion from a first position to a second position, and covers the surface of the substrate at least in the second position so as to cover the surface of the covering member and the substrate Gaps; and Control department And the control part outputs a signal to implement the following steps: An expansion step, rotating the substrate to expand the coating liquid supplied to the substrate to the peripheral edge portion; The air flow forming step then moves the covered member relative to the substrate from the first position to the second position, and at the gap, the air flow is formed to have a flow velocity greater than when the covered member is located at the first position Flow rate; and In the rotation step, the substrate is then rotated at a second rotation speed higher than the first rotation speed, for throwing off the coating liquid at the peripheral portion of the substrate and adjusting the film thickness distribution of the coating film.

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